There are so far been developed an optical disk on which audio signals, for example, are recorded in a digital form, or a so-called compact disk. On the compact disk, all the pieces of music are recorded and to end such that, in case of normal reproduction, the reproduction operation is continued after the end of the reproduction of a piece of music such that the next piece of music follows immediately thereafter.
Since the compact disk is dedicated to reproduction, it is desired that a disk system be evolved in which the disk is recordable and in a relation of superior compatibility with respect to the compact disk. However, in such disk system, all the musical pieces are not always recorded end to end such that an unrecorded portion may exist for example between the first and second pieces of music. If the continuous reproduction operation were performed in this case, the silent portion would be continuously reproduced from the end of the first piece of music until the start of the second piece of music. In case of a so-called overlapped recording, that is, when a new piece of music is recorded over a previously recorded portion, the original musical piece occasionally remaining after the end of the newly recorded musical piece would also be reproduced.
In addition, when performing a recording (sound-recording) operation, it is rather difficult to find the unrecorded portion and a lot of time may be involved in finding such portion.
In view of the above described problems, it is an object of the present invention to provide an apparatus and a method of recording and reproducing data using a disk wherein optimum reproduction can be performed without losses in the reproduction operation even when an unrecorded portion or portions exist between ajoining pieces of music, or when a piece of music shorter than the previously recorded piece of music is recorded overlapped thereon. It is another object of the present invention to provide a method and an apparatus for recording and reproducing data using a disk wherein an unrecorded portion of the disk can be found promptly in the course of the recording (sound recording) operation.